“Inclusion of native gold (greenish grey grain, top right) in polysynthetic twinned famatinite (greenish, brownish, blueish rotation tints), with alteration product cuprite in vugs (crimson-red internal reflections), Reflected light digital image in air with crossed polars. Width of image 0.2 mm. Ore microscopy is the only method that illuminates the darkness of the opaque “grey ugly” with true reflectance colors! G. Grundmann collection and photo. ”

“Inclusion of native gold (bright yellow, top right) in polysynthetic twinned famatinite (pale brownish-pink reflectance pleochroism), with tetraedrite (light-grey), and alteration product cuprite in vug. (reddish internal reflections). Reflected plane polarized light digital image in air. Width of image 0.2 mm. Ore microscopy is the only method that illuminates the darkness of the opaque “grey ugly” with true reflectance colors! G. Grundmann collection and photo. ”